In the gaming industry, gaming machines, especially electronic gaming machines, such as slot machines, video poker machines and the like, have been an important basis. Gaming machines offer a variety of games such as slot games, video poker games, roulette games and many other types of wagering games. The games are commonly deployed on electronic gaming machines (“EGMs”) at a casino or other gaming establishment for use by players, but they may also be deployed on server-based gaming systems or on a general purpose computing devices or mobile phones in stand-alone form or as online games, which is a video game that is either partially or primarily played across a network such as the Internet or another computer network.
Playing such a game (e.g. slot game, video poker game, roulette game, etc.) typically requires placing a wager on the outcome of the game. The games are programmed with a predefined set of outcomes including one or more winning outcomes and one or more losing outcomes. The player is typically awarded for a winning outcome and receives no award for a losing outcome.
A win on a slot game usually involves matching symbols, either on mechanical reels that spin and stop to reveal one or several symbols, or on simulated reels shown on a display device (e.g. video screen, etc.). The reels—either mechanical or simulated—form a matrix with a predetermined number of rows and columns, wherein the number of columns corresponds to the number of reels. Most games have a variety of winning combinations of symbols, often posted on the face of the gaming machine. The outcome of game play is randomly determined—nowadays usually with the help of a random number generator and by a processor or control unit integrated in the EGM. Then, the outcome is displayed in the form of a symbol matrix, wherein the symbols are randomly selected at each position in the symbol matrix, and if a winning combination results within the symbol matrix according to the rules of the game, the EGM provides the player with an award (e.g. credit, points, cash, extra games, etc.).
Generally, the popularity of EGM games depends on the player's expectation of achieving a winning outcome, and on the entertainment value of a particular game compared to other available gaming options. If there are different EGMs available and the expectation of winning at each EGM is roughly the same, players will be attracted to the most exciting and entertaining games. That being the case, there is a continuing need for EGMs providing new and exciting games, or new types of games in the gaming industry which will attract frequent game play by enhancing the entertainment value and the excitement associated with the game.
Various EGMs use methods of expanding the symbol matrix by e.g. adding columns (reels) or rows to increase game variation and player excitement. One example of such a game is disclosed in US 2005/0159208 A1 to Pacey. Pacey discloses an EGM using an expandable symbol array to create a series of sequentially larger symbol arrays with the potential of additional or enhanced awards. The expanded symbol array is created by addition of one or more reels to the base array. The expanded symbol array may be generated only under special circumstances that occur in the base symbol array. In response to the occurrence of these circumstances, at least an additional reel is added to the base symbol array producing a larger symbol array.
US 2013/0065663 A1 to Johnson et al., discloses a slot machine game with expanding positions. The slot machine game of Johnson increases the size of the symbol array as a mystery feature. As the reels are spinning, the number of positions available on each reel grows randomly to allow more paylines. The symbol array is expanded using a mystery feature that adds one or more rows to the symbol array.
Although many existing games entertain and excite players, there is always a need for better and more interesting games and features which provide the players with an ever-increasing level of excitement. Such added excitement may be provided by a dynamic variation of the size of the symbol matrix and thus a varied number of paylines in different game plays.